Jason Bay is too unassuming to crave the status of a legend, but he may have that honor thrust upon him, anyway. With Bay's two-run, two-out, ninth-inning homer off Mariano Rivera at Fenway Park, the man who replaced Manny Ramirez stamped his name in the annals of the Red Sox-Yankees rivalry, probably for years to come.

Kevin Youkilis' one-out homer off Damaso Marte gave Boston an unforgettable 5-4, 11-inning win over New York, but this game belonged to Bay as well.

"Obviously, (Rivera) is about the best in the game at (closing)," said Bay, who connected to left-center on a 1-0 pitch.

"I took a pitch to see it, and I was lucky enough to get the next one out.

"There was a little question that it might hit the wall, which would have been OK, but it was nice to see it go. It's a good feeling, but before you win the game, you can't jump up and down.

"Seeing Youk's ball go out, that was kind of a relief," Bay said.

"I was just looking for a pitch to hit," Youkilis said of his homer to left in the 11th.

"It was just a great, back-and-forth game. I think we'll have a lot of games like that this year."

It was the 900th Red Sox victory over their archrivals since 1903, when the current Yankees established themselves in New York.

Until Bay's home run, the Red Sox had seemed destined to lose in the most frustrating way imaginable, as their own worst enemies.

In the first five innings, Boston hit into four double plays. They also left 13 men on base in the game.

The Red Sox have had periodic success over the years against Rivera, who has dominated just about everybody else.

"We've put a little dent in him from time to time, but we've had more opportunities, too, because we play them more than anybody does," Red Sox manager Terry Francona said.

"It's still not a confidence boost, seeing Mariano come in. But we never give up, we always feel we have a chance.

"Part of it is this ballpark, part of it is having good players, and the atmosphere, too. We always talk about it - if we can get the tying run up, we have a chance."

Youkilis' one-out single in the ninth created that chance. Rivera was poised for a four-out save, when Bay's swing changed everything.

It left the Red Sox with Jonathan Papelbon and eventual winning pitcher Ramon Ramirez available, while Rivera was done and Marte had to come in for New York.

New York left 15 men on base. Leading 4-2 in the ninth, they loaded the bases off Javier Lopez, but did not score.

"That shows great pitching and defense, and that's what wins games," said Youkilis, finding value in the 28 men the teams left on base.

In the 10th, Dustin Pedroia robbed Jeter of a run-scoring hit, and Papelbon fanned Mark Teixeira with two men in scoring position.

Bay plays a little outfield, too. In the seventh, his diving catch in left kept New York's two-run, go-ahead inning from becoming something bigger.